Updated

A police officer who opened fire and killed a knife-wielding robbery suspect had no choice, his chief said Monday.

"This was a vicious, violent attack on the officer," police Chief Eliot Isaac said. "This officer had no other course of action."

Isaac said the attack and shooting Sunday morning were captured on video. He said the city couldn't release the video because it was subpoenaed by the Hamilton County prosecutor's office for a review of the officer's actions to decide whether any charges should be considered.

Police said the slain man, Jawari Porter, was suspected of robbing a Cincinnati grocery store 20 minutes earlier, holding a knife on a security guard. Isaac said two officers investigating the robbery spotted Porter on foot at Government Square downtown and pulled over their vehicle.

Officer Anthony Brucato, a 25-year police veteran, was getting out of the driver's side when Porter charged him, Isaac said. Police said it's believed Brucato fired six times, striking Porter multiple times.

Porter died at the scene.

Brucato had minor injuries, Isaac said. The other officer didn't fire, the chief said.

Mayor John Cranley said: "We could have been in a situation where an officer was killed. This man tried to kill a Cincinnati police officer, viciously."

Court records show Porter was last year ruled incompetent to stand trial and was ordered into mental health treatment.

Hamilton County court documents show a judge in September 2015 found Porter was mentally ill when he had faced charges of assault and resisting arrest. A July 2015 police affidavit stated Porter continued to try to attack an assault victim while and after police used a stun gun on him.

An assistant public defender who represented Porter last year said the office's involvement ended after the case moved to probate court.

Sunday's was the third fatal shooting this year of a suspect by an on-duty Cincinnati police officer.

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